chemistry final review session 1 - may 5, 2011. density density = mass/volume

Chemistry FinalReview Session 1 - May 5, 2011

Density

• Density = Mass/Volume

Density GraphWhat is the density of salt water?

Precision vs accuracy

• accuracy = how close a result is to the ACTUAL value

• precision = how close together a set of results are to one another

Mixtures, compounds

• What is the difference between a mixture and a compound?

Chemical vs physical changes

• Physical change = no change in composition

• Chemical change = change in chemical composition

SI system

• Be able to convert between units

• milli, centi, deci, deca, kilo, etc.

• meters, kilograms, liters,

Ways to separate mixtures

• Physical means of separating mixtures

• Distillation

• Filtration

• Chromatography (pass mixture through a physical medium - smallest molecules travel farthest, etc.)

How to draw a graph

• Descriptive Title

• Scale for maximum coverage of graph area

• Set Origins for maximum expression of data features

• Axis Labels with Units

• Points clearly indicated

• Smooth curve, not dot-to-dot

Nomenclature - IOnic

• MgCl2

• NaNO3

• Fe2O3

• FeO

• NaC2H3O2

Writing compounds

• You have an ionic compound of Aluminum and the polyatomic ion sulfate. What is the correct formula?

• What is the correct formula for Calcium Oxide?

• What is the correct formula for Cu(II) Hydroxide?

Covalent nomenclature

• H2O

• NO

• SO2

• CSe2

Moles

• How many moles of Oxygen atoms in 3 moles of water?

• What is the molar mass of CO2? C6H12O6?

• How many atoms in 3 moles of B2O3?

Percent composition

• What is the percent composition of Carbon in CO2?

Empirical formula

Butyric acid gets its name from the Latin "butyrum", meaning butter, and is the compound in rancid butter that gives it its terrible smell. A 2.50 g sample of butyric acid was found to consist of 1.36 g carbon, 0.23 g hydrogen, and 0.91 g oxygen. Find its empirical formula.

Empirical formula

• Natural gas is a mixture of several hydrocarbons, but is primarily methane. Find the empirical formula of this important natural resource if its composed of 74.8% carbon and 25.2% hydrogen

Molecular formula

• The simplest formula for vitamin C is C3H4O3. Experimental data indicates that the molecular mass of vitamin C is about 180. What is the molecular formula of vitamin C?

BAlancing equations

• Balance the following equations:

• ____ Na3PO4 + ____ KOH ____ NaOH + ____ K3PO4

• ____ Na3PO4 + ____ CaCl2 ____ NaCl + ____ Ca3(PO4)2

• ____ CH4 + ____ O2 ____ CO2 + ____ H2O

Types of reactions

• A + B --> AB

• AB --> A + B

• AB + C --> CB + A

• AB + CD --> AD + CB

• Hydrocarbon + O2 --> CO2 + H2O + heat